PS2 (Ext)-6
Students demonstrate an understanding of physical, chemical, and nuclear changes by... 6aa-using chemical equations and information about molar masses to predict quantitatively the masses of reactants and products in chemical reactions.
National Standards:
Context of Lesson:
Students will be exploring the relationship between the concept of a mole and an element's molar mass. They will learn how to correctly use the mole (do you mean molar mass?) as a conversion factor to go from an element's/compound's mass to number of moles. If time permits, students will complete Part I of the laboratory exercise: Making Cents of Penny Composition. Lesson Duration: 90 minutes.
Opportunities to Learn:
Depth of Knowledge
Prerequisite Knowledge
Gmm, gam, and gfm
The concept of the mole
Linear conversions
Plans for Differentiating Instruction
To strengthen both math and language skills have students write out the conversions without any numbers just the labels so students can better see the path of the conversion. Will this help students understand that each conversion factor must equal one?
Accommodations and modifications
Environmental factors
There is a smartboard which can be used for demonstration purposes. Desks are set up in rows.
Materials
Students will need their calculators
(Time Dependent) Refer to the materials list for Part I of the laboratory exercise: Making Cents of Penny Composition
Objectives:
Students will use the molar mass to convert between mass and number of moles of a substance
Instruction:
Opening:
Ask the following question about the reading: What is the molar mass of Oxygen? (Answer to follow later in opening)
Review what was accomplished during the previous class (gam, gmm, gfm). Explain to students that although the terms gram atomic mass (gam), gram molecular mass (gmm), and gram formula mass (gfm) all have different specific meanings, we can use a much broader term to encompass these three concepts: Molar Mass
Molar mass can be defined as the mass (in grams) of one mole of any substance. However, there are some problems that can arise with this. If I were to ask you: "What is the molar mass of Oxygen?", there may be some problems accurately answering the problem, why? Answer: Because Oxygen can exist as an element (O) and as a molecule (O2). Why don't you let this question hang for a bit before answering it?
So, to avoid confusion you will be told which to use. Always?
Engagement:
Let's take a look at an example problem: Say I wanted to know how many grams are in 9.45 mol of dinitrogen trioxide (N2O3).
First, we must map out our problem so we can determine how to accurately calculate the answer. In this case we are going from moles of N2O3 to grams of N2O3.
Second, we must determine the molar mass of N2O3, which is? Answer: 76.0g Will you give students a chance to determine this based on yesterday's lesson?
Third, we need to set up our linear conversion: 9.45 mol N2O3 x 76.0g N2O3/1 mol N2O3
Last, we obtain our answer, which is? Answer: 718.2g N2O3
At this time ask if there are any questions about the example we have just done. After questions are answered move on to practice problems to reinforce the example just gone over.
Let's look at some problems now. Find the mass, in grams, of each of the following substances:
3.32 mol K
4.52x10^-3 mol C20H42
0.0112 mol K2CO3
For these problems be sure to review the steps if students appear to be having trouble.
For these next set of problems we will will be doing the reverse conversion of the ones done in the previous problem. Please find the number of moles in each of the following quantities:
3.70x10^-1 g B
27.4 g TiO2
847 g (NH4)2CO3 (Review: What does the subscript 2 after NH4 mean? Answer: It means there are 2 NH4's, or 2 N and 8H, present in the compound)
After the problems are completed be sure to go over what types of problems were demonstrated. In the first problem we converted from moles to grams and in the second problem we converted from grams to moles. Are some of these problems "challenge" problems? If not, why not have some to let the students who understand apply the technique for some more challenging example. What is the molar mass of a DNA molecule?
Depending on how much time is left in the period will depend on whether or not we will be able to start Part I of the laboratory exercise: Making Cents of Penny Composition.
Closure:
End the class with a review of what was gone over (conversions from moles to grams and grams to moles). How far we are able to get through Part I of the laboratory exercise will depend solely on how well the majority of the class is able to grasp the material presented in the practice problems. If Part I is incomplete continue with it the following class. If it is completed take time at the end of the class to review student's results from the data that they have obtained.
Assessment:
Students will be formatively assessed via questions posed throughout the lesson designed to assess their grasp on the material. They will also receive a formative assessment on their ability to follow directions and practice safe laboratory procedures. Provided that there was time to complete them, students' data sheets will be turned in and graded at the beginning of the following class. Anyone who has completed their data collection but not their data sheet must finish it for homework.
You should save time for students to put examples on board so that you can make sure that they understand the process. Are you going to collect this work and grade it?
Solid activities. It would be nice if you could do more to relate this process either to real-life counting or chemistry.
Lesson Plan
Lesson Title: Mole-Mass Relationships
State Standards: GLEs/GSEs
PS2 (Ext)-6Students demonstrate an understanding of physical, chemical, and nuclear changes by...
6aa-using chemical equations and information about molar masses to predict quantitatively the masses of reactants and products in chemical reactions.
National Standards:
Context of Lesson:
Students will be exploring the relationship between the concept of a mole and an element's molar mass. They will learn how to correctly use the mole (do you mean molar mass?) as a conversion factor to go from an element's/compound's mass to number of moles. If time permits, students will complete Part I of the laboratory exercise: Making Cents of Penny Composition. Lesson Duration: 90 minutes.Opportunities to Learn:
Depth of Knowledge
Prerequisite Knowledge
Plans for Differentiating Instruction
To strengthen both math and language skills have students write out the conversions without any numbers just the labels so students can better see the path of the conversion. Will this help students understand that each conversion factor must equal one?Accommodations and modifications
Environmental factors
There is a smartboard which can be used for demonstration purposes. Desks are set up in rows.Materials
Objectives:
Instruction:
Opening:
Ask the following question about the reading: What is the molar mass of Oxygen? (Answer to follow later in opening)Review what was accomplished during the previous class (gam, gmm, gfm). Explain to students that although the terms gram atomic mass (gam), gram molecular mass (gmm), and gram formula mass (gfm) all have different specific meanings, we can use a much broader term to encompass these three concepts: Molar Mass
Molar mass can be defined as the mass (in grams) of one mole of any substance. However, there are some problems that can arise with this. If I were to ask you: "What is the molar mass of Oxygen?", there may be some problems accurately answering the problem, why? Answer: Because Oxygen can exist as an element (O) and as a molecule (O2). Why don't you let this question hang for a bit before answering it?
So, to avoid confusion you will be told which to use. Always?
Engagement:
Let's take a look at an example problem: Say I wanted to know how many grams are in 9.45 mol of dinitrogen trioxide (N2O3).At this time ask if there are any questions about the example we have just done. After questions are answered move on to practice problems to reinforce the example just gone over.
Let's look at some problems now. Find the mass, in grams, of each of the following substances:
- 3.32 mol K
- 4.52x10^-3 mol C20H42
- 0.0112 mol K2CO3
For these problems be sure to review the steps if students appear to be having trouble.For these next set of problems we will will be doing the reverse conversion of the ones done in the previous problem. Please find the number of moles in each of the following quantities:
- 3.70x10^-1 g B
- 27.4 g TiO2
- 847 g (NH4)2CO3 (Review: What does the subscript 2 after NH4 mean? Answer: It means there are 2 NH4's, or 2 N and 8H, present in the compound)
After the problems are completed be sure to go over what types of problems were demonstrated. In the first problem we converted from moles to grams and in the second problem we converted from grams to moles. Are some of these problems "challenge" problems? If not, why not have some to let the students who understand apply the technique for some more challenging example. What is the molar mass of a DNA molecule?Depending on how much time is left in the period will depend on whether or not we will be able to start Part I of the laboratory exercise: Making Cents of Penny Composition.
Closure:
End the class with a review of what was gone over (conversions from moles to grams and grams to moles). How far we are able to get through Part I of the laboratory exercise will depend solely on how well the majority of the class is able to grasp the material presented in the practice problems. If Part I is incomplete continue with it the following class. If it is completed take time at the end of the class to review student's results from the data that they have obtained.Assessment:
Students will be formatively assessed via questions posed throughout the lesson designed to assess their grasp on the material. They will also receive a formative assessment on their ability to follow directions and practice safe laboratory procedures. Provided that there was time to complete them, students' data sheets will be turned in and graded at the beginning of the following class. Anyone who has completed their data collection but not their data sheet must finish it for homework.You should save time for students to put examples on board so that you can make sure that they understand the process. Are you going to collect this work and grade it?
Solid activities. It would be nice if you could do more to relate this process either to real-life counting or chemistry.
Reflections
(only done after lesson is enacted)Student Work Sample 1 – Approaching Proficiency:
Student Work Sample 2 – Proficient:
Student Work Sample 3 – Exceeds Proficiency: